This invention relates to an improved method of producing cotton bales. More particularly, this invention relates to a method of producing baled lint cotton with small moisture absorbing and emitting property.
Cotton bales are produced generally by subjecting collected seed cotton to a ginning process whereby seeds and cotton fibers are separated, removing burrs, leaves, stems and other trash from the separated fibers to obtain lint cotton, and compressing the lint cotton. For reasons of practicality in the trade of cotton bales, seed cotton or lint cotton or a low quality which would adversely affect the commercial value of the produced cotton bale may be removed and water may be sprayed to the seed cotton or lint cotton in order to roughly adjust their moisture regain during their production process.
Since seed cotton and lint cotton which is obtained therefrom are mainly composed of cellulose fibers, they absorb and emit moisture more strongly than synthetic fibers such as polyesters and nylon and their moisture regain varies significantly by the changes in the temperature and humidity of the environment. Moreover, quality of seed cotton and lint cotton, such as the amount of sugar contents, the amount of so-called honeydew (insect secretion) which is attached and the amount of mixed unripe fibers, varies greatly, depending on the climate and soil conditions of the region, the method of planting and their variety. The greater their amounts, the greater the hygroscopicity as compared to normal cotton.
The moisture regain of cotton bales produced by a conventional method as described above changes significantly due to changes in the environmental conditions such as temperature and humidity because of the moisture absorbing and emitting property of seed cotton and lint cotton obtained therefrom. For this reason, cotton bales produced by a conventional method have the following problems.
Firstly, if cotton bales from lint cotton, which was already high or normal in moisture regain, absorb more humidity from the environment while they are being stored or being transported, they are easily mildewed or invaded by bacteria. As a result, they may become discolored or malodorous, or their strength may be adversely affected.
Secondly, if baled lint cotton absorbs moisture from the environment while being stored or transported such that the official moisture regain is exceeded, it is commercially a very significant disadvantage.
Thirdly, high-density compressed cotton bales are advantageous because the cost of their transportation and storage is low. For this reason, it is a common practice to preliminarily apply moisture to baled lint cotton such that its moisture regain becomes about 9-11%. This is so as to humidify the cotton fibers and to thereby reduce their Young's modulus such that they can be compressed more efficiently. This method is being practiced both in India and in Pakistan where cotton bales of density 520-570 kgs/m.sup.3 are being produced. High-density cotton bales thus produced suffer from the fatal disadvantage explained above.
Fourthly, such high-density cotton bales do not return efficiently to the original condition before the compression and this adversely affects the handling of cotton blocks after the bales are opened.